KR20040070563A - Plasma display panel - Google Patents

Abstract

PURPOSE: A plasma display panel is provided to achieve improved luminance and efficiency and lower a discharge start voltage without causing an additional power consumption. CONSTITUTION: A plasma display panel comprises a front panel(40) having first and second discharge sustain electrodes(42,44) and first and second bus electrodes(46,48) attached to the discharge sustain electrodes; and a rear panel(60) having an address electrode(62). One of the bus electrodes has a thickness having an opposed surface so as to cause a counter discharge with respect to the other of the bus electrodes.

Description

Plasma display panel {Plasma display panel}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display device, and more particularly, to a surface discharge plasma display panel (hereinafter referred to as PDP) having some counter discharge effects.

PDP puts Ne + Ar, Ne + Xe, etc. gas between the front glass and the back glass and the glass enclosed by the partition between them, and applies voltage to the anode and the cathode. Is an electronic display device that emits light and uses the same as display light.

PDP has many advantages that are suitable for large-sized display among various flat panel displays such as liquid crystal display (LCD), field emission display (FED), and electro-luminescence display (ELD), which are being actively studied.

The reason why PDP can be enlarged as a flat plate is to use two glass substrates each having a thickness of about 3 mm, apply appropriate electrodes and phosphors on each substrate, and maintain a space between them by keeping a gap of about 0.1 to 0.2 mm. This is because a method of forming a plasma is adopted.

PDP has the following features.

1. Has strong nonlinearity.

Even when a voltage is applied between the electrodes, no discharge occurs for an applied voltage below the discharge start voltage.

2. It has a memory function.

The PDP has a memory function in which the next state is determined by the condition of the previous state due to the wall charge. In the case of driving by the memory driving method using such a memory function, it is possible to express a high quality image even for a very large panel without lowering the luminance.

3. It has a long life.

In the case of an AC PDP, since a protective film such as magnesium oxide film (MgO) having excellent resistance to sputtering exists on the dielectric film, the service life is extended.

Currently commercialized products have a lifespan of over 20,000 hours, and in principle over 100,000 hours.

4. It has high brightness and high luminous efficiency.

PDP has been developed an AC type PDP having a luminance of 350 ㏅ / ㎡ and an efficiency of about 1 ㏐ / W, but the high efficiency of 500 cd / m ² or more and 4 ㏐ / W of high efficiency is possible in theory of gas discharge phenomenon. However, considering that the peak luminance of the CRT is 700 μs / m ² and the efficiency is several μs / W, the luminance and efficiency of the PDP need to be further improved. It is expected to be achieved by improving the UV radiation efficiency of the phosphor, improving the visible light conversion efficiency of the phosphor.

5. Wide viewing angle.

PDP is a self emissive display device, and its viewing angle is extremely wide. Both AC and DC models have wide viewing angles of up to 160 ° left and right, comparable to CRTs.

6. Full color can be easily implemented.

The color implementation of the PDP utilizes a photoluminescence mechanism in which ultraviolet rays formed in the discharge stimulate the fluorescent film to emit visible light. Therefore, color reproduction of CRT level is possible.

7. The manufacturing cost can be lowered.

As a substrate of the PDP, soda-lime glass, which is widely used, is used. Materials such as electrodes, dielectric films and barrier ribs can also be manufactured at low cost. Therefore, if mass production process technology is established, it can be mass-produced at low cost.

8 . Heat resistant cold resistance.

The PDP is hardly affected by the plasma generated in each pixel when the temperature of the barrier ribs or the electrodes is about -100 ?? to 100 ??. Therefore, it can be said that the operating temperature range of the PDP is determined by the semiconductor element used in the driving circuit.

9. Light weight is possible.

The 40-inch CRT will weigh more than 100 kilograms of TV sets. PDPs, on the other hand, weigh about 30 kg in sets of the same size, which can be further reduced by lighter components.

10. It has seismic characteristics.

Unlike CRT and VFD, PDP does not use filament, so it has good seismic characteristics. And there is no danger like the inner width of the CRT.

11. Has high resolution.

PDP is ultimately a suitable display device for HDTV, and a cell pitch of about 300 μm has already been realized through a monochrome PDP. The color PDP can be made with the same technology, but the PDP characteristics developed so far show that cell pitch and luminance tend to be inversely proportional. In order to make a PDP having a high resolution while maintaining a high efficiency, a more effective high temperature, high density plasma forming technique is required.

12. A high voltage drive circuit is needed.

Currently, pulses having a voltage and a frequency of about 150 to 200 V and about 70 to 80 kHz are used for driving a PDP. Therefore, driving IC of high breakdown voltage is necessary for PDP driving.

However, due to the high price of high voltage resistance ICs, the ratio of high voltage resistance ICs to total panel prices is very high. Therefore, it is necessary to reduce the driving IC cost by lowering the driving voltage and improving the driving method.

1 shows a perspective view of an AC PDP according to the prior art having such characteristics.

Referring to FIG. 1, a conventional PDP includes a front glass substrate 10 and a rear glass substrate 12 facing in parallel with the front glass substrate 10. Transparent first and second sustaining electrodes 14a and 14b are arranged in parallel on a surface facing the rear glass substrate 12 of the front glass substrate 10 (hereinafter referred to as “back side”). It is. The first and second discharge sustain electrodes 14a and 14b have a gap g1 therebetween as shown in FIG. First and second bus electrodes 16a and 16b are disposed on the first and second discharge sustain electrodes 14a and 14b, respectively, in parallel with the respective discharge sustain electrodes 14a and 14b. The first and second bus electrodes 16a and 16b prevent a voltage drop due to resistance during discharge. The first and second discharge sustain electrodes 14a and 14b and the first and second bus electrodes 16a and 16b are covered with a first dielectric layer 18, and the first dielectric layer 18 is covered with a protective film 20. Covered. The passivation layer 20 protects the first dielectric layer 18 having low durability from discharge so that the PDP can operate stably for a long time, and at the same time, discharge a large amount of secondary electrons during discharge to lower the discharge voltage. As such a protective film 20, a magnesium oxide film (MgO) is widely used.

On the other hand, a plurality of address electrodes 22 for writing data on the back glass substrate 12 are formed. The address electrodes 22 are all arranged in parallel, but are arranged perpendicularly to the first and second discharge sustain electrodes 14a and 14b. Three address electrodes 22 are provided per pixel. In one pixel, the three address electrodes 22 correspond one-to-one with a red phosphor, a green phosphor, and a blue phosphor, respectively. A second dielectric layer 24 covering the address electrode 22 is formed on the rear glass substrate 12, and a plurality of barrier ribs 26 are provided on the second dielectric layer 24. The second dielectric layer 24 is for light reflection. The plurality of partitions 26 are spaced apart by a given interval and are parallel to the address electrode 22. Each partition 26 is located on the second dielectric layer 24 between the address electrodes 22. In other words, the address electrodes 22 and the partition walls 26 are alternately arranged. The partition wall 26 is in close contact with the protective film 20 provided on the rear surface of the front glass substrate 10 in the process of bonding the front and rear glass substrates 10 and 12. Phosphors 28a, 28b and 28c are applied between the partitions 26. The first phosphor 28a is excited by ultraviolet light to emit red (R) light, the second phosphor 28b to emit green (G) light, and the third phosphor 28c to emit blue (B) light, respectively. do.

After the front and back glass substrates 10 and 12 are hermetically bonded to each other, unnecessary gas is exhausted between the two glass substrates 10 and 12, and then a plasma forming gas is injected. The plasma forming gas may be a single gas (eg, Ne), but a mixed gas (eg, Ne + Xe) is generally used.

In the case of the PDP according to the related art, it is possible to implement a large screen and has a wide viewing angle. However, the luminance and the efficiency are much lower than those of the CRT. Required. However, rising power consumption means higher voltage driving, which requires better driving ICs. This result is contrary to the current trend because it leads to an increase in PDP prices with an increase in power consumption.

SUMMARY OF THE INVENTION The present invention has been made in an effort to improve the above-described problems of the prior art, and to provide a PDP capable of reducing the discharge start voltage while improving luminance and efficiency without increasing power consumption.

1 is a perspective view of an AC plasma display panel according to the prior art.

FIG. 2 is a perspective view separately showing only a sustaining electrode and a bus electrode of the plasma display panel of FIG. 1.

3 is a cross-sectional view of the front panel of the AC PDP according to the embodiment of the present invention.

4 is a cross-sectional view of the rear panel constituting the AC type PDP according to the embodiment of the present invention facing the front panel shown in FIG.

5 and 6 are cross-sectional views illustrating a case in which the thicknesses of the two discharge sustaining electrodes provided in the front panel of FIG. 3 are changed.

7 is an exploded perspective view of an AC PDP according to an embodiment of the present invention having the front and rear panels shown in FIGS. 3 and 4.

8 to 11 are exploded perspective views showing a modification of the AC type PDP shown in FIG.

12 to 14 are graphs showing experimental results of the AC PDP shown in FIG. 7.

* Description of Signs of Major Parts of Drawings *

40: front panel 42, 44: first and second discharge holding electrodes

46 and 48: first and second bus electrodes t1 to t5: first to fifth thicknesses

50: dielectric film 52: protective film

60: rear panel 62: address electrode

64: dielectric film 66: partition wall

68: fluorescent layer 70: discharge area

In order to achieve the above technical problem, the present invention provides an AC-type PDP having a front panel having a discharge holding electrode and a bus electrode attached to the discharge holding electrode and a rear panel having an address electrode, wherein the bus electrode is Provided is a PDP, which is formed to a thickness having a predetermined opposing surface so as to cause an opposite discharge with another adjacent bus electrode.

The other bus electrode is formed to a thickness having the same opposite surface as the bus electrode. At this time, the thickness is at least 14 μm.

The other bus electrode has a thickness without an opposing face to the bus electrode.

The other bus electrode is formed to have a thickness having a surface facing the bus electrode, but is thinner than the thickness of the bus electrode.

The address electrode is the same thickness as the bus electrode.

The front panel includes a dielectric film and a protective film covering the discharge sustaining electrode and the bus electrode, wherein at least portions of the two films on which the bus electrode is formed are convex toward the rear panel.

In the case of the PDP according to the present invention, since the main discharge has some counter discharge elements even though the surface discharge is a surface discharge, both the brightness and the efficiency can be improved without additional power consumption, and the discharge start voltage can also be lowered.

Hereinafter, a PDP according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of layers or regions illustrated in the drawings are exaggerated for clarity.

Figure 3 is a cross-sectional view of the front panel portion of the PDP according to an embodiment of the present invention, for convenience and understanding of the illustration, it is shown so that the portion facing the rear panel on the front panel on the front glass substrate.

Specifically, referring to FIG. 3, the first and second discharge sustain electrodes 42 and 44 are arranged side by side in a stripe shape on the front glass substrate 40. The first and second discharge sustain electrodes 42 and 44 are spaced apart by a predetermined interval suitable for discharge. A positive voltage for initiating a discharge is applied to one of the first and second discharge sustain electrodes 42 and 44, and a negative voltage is applied to the other. First and second bus electrodes 46 and 48 are formed in a stripe shape on the first and second discharge sustain electrodes 42 and 44, respectively. The first and second bus electrodes 46 and 48 are electrodes made of Ag. The first and second bus electrodes 46 and 48 are formed to have first and second thicknesses t1 and t2, respectively. In this case, the first and second thicknesses t1 and t2 are much thicker than the thicknesses of the first and second discharge sustain electrodes 42 and 44 as well as the conventional bus electrodes 16a and 16b of FIG. 2. desirable. In addition, the thicknesses t1 and t2 of the first and second bus electrodes 46 and 48 are preferably the same, and more preferably a thickness thick enough to have opposing surfaces, for example, 14 μm or more.

The first and second bus electrodes 46 and 48 are formed on the first and second discharge sustain electrodes 42 and 44 by a predetermined forming method, for example, a thick film printing method. The bus electrodes 42 and 44 having the first and second thicknesses t1 and t2 may be formed of a thin film having a much higher conductivity than the first and second discharge sustain electrodes 42 and 44, such as silver foil. And printing on the second discharge sustain electrodes 42 and 44 at least three times using the thick film printing method.

As such, since the first and second bus electrodes 46 and 48 are formed to have a thickness sufficient to have opposing surfaces, surface discharge occurs between the first and second discharge sustain electrodes 42 and 44. At the same time, the opposite discharge occurs between the first and second bus electrodes 46 and 48 although the specific gravity thereof is lower than that of the surface discharge.

As such, the first and second bus electrodes 44 and 46 are used for discharging in the form of counter discharge, whereby the electrode group composed of the first discharge sustaining electrode 42 and the first bus electrode 46 and the second discharge sustaining are provided. The discharge efficiency between the electrode group composed of the electrode 44 and the second bus electrode 48 is much higher than in the prior art. This increase in discharge efficiency results in increased brightness and efficiency of the PDP.

3, the dielectric film 50 covering the first and second discharge sustain electrodes 42 and 44 and the first and second bus electrodes 46 and 48 on the front glass substrate 40. ) And the protective film 52 are sequentially formed. The protective film 52 is an MgO film. Due to the thickness of the first and second bus electrodes 46 and 48, the dielectric film 50 and the passivation film 52 are formed at the portion where the first and second bus electrodes 46 and 48 are formed. It protrudes by the thicknesses t1 and t2 of the electrodes 46 and 48. In the PDP, the front panel including the first and second bus electrodes 46 and 48 is opposite to the rear panel, so that the dielectric film 50 and the portion of the first and second bus electrodes 46 and 48 are provided. The distance between the passivation layer 52 and the rear panel is as much as the first and second thicknesses t1 and t2 of the first and second bus electrodes 46 and 48 than the dielectric layer 50 and the passivation layer 52 formed in the other portion. It becomes narrower.

FIG. 4 shows a cross section in a direction perpendicular to the address electrode 62 of the rear panel facing the front panel shown in FIG.

Referring to FIG. 4, an address electrode 62 is formed on the rear glass substrate 60 to have a third thickness t3. The address electrode 62 is formed perpendicular to the discharge sustain electrodes 46 and 48 and the bus electrodes 46 and 48. The third thickness t3 of the address electrode 62 is at least 14 µm or more, which is much thicker than that of the conventional PDP address electrode (22 in FIG. 1). Accordingly, a step corresponding to the third thickness t3 is formed between the region where the address electrode 62 is present and the region where the address electrode 62 is not. A dielectric film 64 having a predetermined thickness covering the address electrode 62 is formed on the rear glass substrate 60. The dielectric layer 64 is thinner than the third thickness t3 of the address electrode 62. Therefore, even after the dielectric film 64 is formed, the step due to the address electrode 62 is shown as it is. A partition 66 is formed on the dielectric film 64 on both sides of the address electrode 62. The partition 66 is symmetric about the address electrode 62 and is parallel to the address electrode 62. The fluorescent layer 68 is applied to the entire surface of the dielectric film 64 between the partitions 66 and the entire surface of the partition 66 facing each other. The inner region 70 of the fluorescent layer 68 is a region where plasma is formed. Since the address electrode 62 has a third thickness t3, the step trace due to the address electrode 62 remains even after the fluorescent layer 68 is formed. As described above, since the third thickness t3 of the address electrode 62 is much thicker than that of the related art, the degree of protrusion of the fluorescent layer 68 formed on the address electrode 62 is higher than that of the related art. As a result, the distance between the address electrode 62 and the first and second discharge sustain electrodes 42 and 44 of the front panel becomes much smaller than before.

Meanwhile, as described above, the first and second thicknesses t1 and t2 of the first and second bus electrodes 46 and 48 in the front panel shown in FIG. 4 are preferably the same, but either One thickness may be different from the other thickness.

5 and 6 show an example of this, while FIG. 5 shows that the first bus electrode 46 is a much thicker first thickness t1 than the prior art, while the second bus electrode 48 has a fourth thickness similar to the prior art. 6 illustrates a case in which the second bus electrode 48 has a fifth thickness t5 that is an intermediate thickness, rather than the first thickness t1 of the first bus electrode 46. Although thin, the case has a thickness thicker than the fourth thickness t4 shown in FIG. 5.

7 to 11 show an exploded perspective view of the PDP composed of the front panel and the rear panel described above. Specifically, FIG. 7 shows that the first and second bus electrodes 46 and 48 are formed of the first and second thicknesses. 3 shows a PDP composed of the front panel shown in FIG. 3 having t1 and t2 and the back panel shown in FIG. 4 having a third thickness t3 which is much thicker than the prior art. 8 shows that the front panel and the address electrode 62 shown in FIG. 3 having the first and second bus electrodes 46 and 48 having the first and second thicknesses t1 and t2 have the same thickness as before. Shows a PDP consisting of a back panel with 9 and 10 respectively show the case where the first bus electrode 46 has the same thickness as the conventional case and the second bus electrode 48 has the same thickness as the conventional case in the PDP shown in FIG. FIG. 11 shows a case in which the thickness of the second bus electrode 48 in the PDP shown in FIG. 7 has a fifth thickness t5 of intermediate thickness as shown in FIG.

12 and 13 illustrate thicknesses and widths of the first and second bus electrodes 46 and 48 according to the number of printing in the process of forming the first and second bus electrodes 46 and 48 according to the thick film printing method. The change is shown by dividing it before and after.

In FIG. 12, reference numeral G1 denotes first and second graphs showing thickness changes of the first and second bus electrodes 46 and 48 measured before firing and G2 after firing.

Referring to the first and second graphs G1 and G2, it can be seen that the thicknesses of the first and second bus electrodes 46 and 48 increase in proportion to the number of printing, and the thickness decreases slightly after firing. It can be seen that.

In practice, the first and second bus electrodes 46 and 48 can be formed up to 60 μm before a predetermined time, but after firing this thickness is lowered to 50 μm.

In FIG. 13, reference numerals G3 and G4 are third and fourth graphs showing a change in width before and after firing of the first and second bus electrodes 46 and 48 according to the number of printing.

Referring to the third and fourth graphs, it can be seen that the area does not change significantly before and after firing as the number of prints exceeds three times.

FIG. 14 illustrates luminance and efficiency characteristics of a PDP according to an embodiment of the present invention. When the thicknesses of the first and second bus electrodes 46 and 48 are about 3 μm, the luminance ( brightness) was about 125 cd / m 2, but when the thickness is 14 μm, the brightness is close to 200 cd / m 2. In this way, in the case of the PDP according to the present invention, the luminance is improved by 40% or more.

The efficiency is also improved by more than 20%. When the thickness of the first and second bus electrodes 46 and 48 is 3 μm, the efficiency is only about half of 0.3 lm / W and 0.4 lm / W. When it became 14 micrometers, it turns out that it approaches 0.4 lm / W.

Although the brightness and efficiency increase as the thicknesses of the first and second bus electrodes 46 and 48 are increased, the voltage required for discharge is about 250V and the first and second bus electrodes 46, It can be seen that there is little change according to the thickness change of 48), and the current is also constant as about 20 mA.

Although not shown in the drawings, the brightness and efficiency characteristics as shown in FIG. 14 are maintained even after the PDP stabilization step and the aging step, which are performed after the PDP formation is completed by combining the front and rear panels. It became.

While many details are set forth in the foregoing description, they should be construed as illustrative of preferred embodiments, rather than to limit the scope of the invention. For example, one of ordinary skill in the art may have a larger dielectric film thickness to flatten the protruding portions of the dielectric film due to the presence of the first and second bus electrodes. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

As described above, in the case of the AC type PDP according to the present invention, since the bus electrode has a thickness sufficient to cause counter discharge, the surface discharge, which is the main discharge, is made by the discharge sustaining electrode. The counter discharge is caused by the bus electrode. In addition, the address electrode provided on the rear panel may be provided with a much thicker thickness than the prior art according to the selection. Therefore, in the case of using the PDP according to the embodiment of the present invention, even though the main discharge is a surface discharge, part of the discharge is made as a counter discharge, so that both brightness and efficiency can be improved without additional power consumption, and discharge starts. The voltage can also be lowered.

Claims (6)

An AC type PDP having a front panel having a discharge holding electrode and a bus electrode attached to the discharge holding electrode and a rear panel having an address electrode, And the bus electrode is formed to a thickness having a predetermined opposing surface so as to cause an opposite discharge with another adjacent bus electrode. The PDP according to claim 1, wherein the other bus electrode is formed to have a thickness having the same opposing surface as the bus electrode. 2. The PDP of claim 1, wherein the other bus electrode is formed to have a thickness that does not face the bus electrode. The PDP of claim 1, wherein the other bus electrode is formed to have a thickness having an opposing surface with respect to the bus electrode, and is formed thinner than the thickness of the bus electrode. The PDP according to any one of claims 1 to 4, wherein the address electrode is formed to have the same thickness as the bus electrode. The method of claim 1, wherein the front panel is provided with a dielectric film and a protective film covering the discharge sustaining electrode and the bus electrode, wherein at least a portion of the two films formed with the bus electrode is convex toward the rear panel. PDP.